1. Mercedes have separated the hot side of the turbo (in red) from the cold side (in blue) and have the MGU-H mounted in the 'V' of the engine between the two parts of the turbo.

2.The heat transfer between the two parts of the turbo is minimised, so less cooling is required to keep the charge air temperature down (or if the same cooling capacity is used, the charge air temperature will be lower, giving more power to the rear wheels).

3. having the MGU-H mounted between the two sides of the turbo could allow Mercedes to have either or both sides working through one-way clutches, making the complete unit more efficient.

4. Basically the exhaust gases coming out of the engine on the hot side of the turbo only ever have to drive the cold side of the turbo and/or the MGU-H, creating electrical power from this component and feeding it directly to the MGU-K.

5. The MGU-H only ever has to drive the cold side of the turbo, increasing the charge air pressure, thus reducing turbo lag and increasing power.

6. The potential advantages of the Mercedes concept could be significant over the course of the season, especially as retro fitting a similar solution will be very difficult for the other power unit manufacturers.

7. personal note: the way mercedes engine packs it's exhaust manifold means the MGU-K is less affected by the heat of the exhaust pipes. this can be significant in the performance of the MGU-K motor unit.

1.Renault have the hot side of the turbo (shown in red) bolted directly to the cold side (in blue).

2.There is heat insulation between them, but there will inevitably still be a lot of heat transfer between the two parts, meaning that a larger intercooler and more airflow will have to be used to reduce the charge air temperature.

3.Mounted to the cold side of the turbo is the MGU-H, which will drive or be driven by the turbo through a central shaft. With this packaging both turbo elements will be driven simultaneously (whereas Mercedes' solution offers the possibility of driving the two elements independently).

4.Mounted to the cold side of the turbo is the MGU-H, which will drive or be driven by the turbo through a central shaft. With this packaging both turbo elements will be driven simultaneously (whereas Mercedes' solution offers the possibility of driving the two elements independently).

5. Personal note: both Ferrari and Renault have extended exhaust manifold that curves around the MGU-K unit. this configuration usually provides good exhaust pressure for the turbo , but is bulky and less packaging efficient.

As to whether I have proof that Renault are running separate works Customer deals the answer is no. But it's worth looking at available evidence. Red Bull Technologies embedded software analysts at Viry resulting in improved performance in Melbourne. Red Bull also prevented sharing of those updates with Lotus and Caterham.
What I found most amusing was that Marko was quoted in AMUS that once Renault cut the power deficit to Mercedes to 40bhp they would be matching Mercedes AMG. Taffin's confirmed in Shanghai that their projected power deficit was now only 40bhp.
It's interesting that for the past 3 seasons Red Bull have won the championship having a car with the lowest top speed of the leading runners. That approach might work if you can blow the diffusor, it does not look like it's going to work this year. Let's face it Mercedes are also the quickest in high down force sectors as well. If Red Bull can't beat The Mercedes in Barca, then we can wheel the fat lady onto the stage.

regarding the ferrari PU, my whole view is that it's not the weight that's the issue, rather the high COG. if we look at merc PU, it sits very low with all the ancilaries well below the engine plenum chamber (let's take that as reference ). the way ferrari exhaust manifold curves upward and the location of the turbine must cause headache to the vehicle dynamics boffins.

also interesting to note is that merc PU is supposed to be sacrificing around 15-20 HP because of the shorter exhaust manifold. (from the autosprint article posted above). also that merc compressor is larger. but due to bad google translation, i couldn't understand most of it, and weather it has any benefit. it says something about RPM and engine breaking and how merc MGU-H can bypass the battery and provide power directly to MGU-K and how the compressor bleed off can give more juice to MGU-K.

can anyone with italian knowledge please translate it better than google translate.

As to whether I have proof that Renault are running separate works Customer deals the answer is no. But it's worth looking at available evidence. Red Bull Technologies embedded software analysts at Viry resulting in improved performance in Melbourne. Red Bull also prevented sharing of those updates with Lotus and Caterham. What I found most amusing was that Marko was quoted in AMUS that once Renault cut the power deficit to Mercedes to 40bhp they would be matching Mercedes AMG. Taffin's confirmed in Shanghai that their projected power deficit was now only 40bhp. It's interesting that for the past 3 seasons Red Bull have won the championship having a car with the lowest top speed of the leading runners. That approach might work if you can blow the diffusor, it does not look like it's going to work this year. Let's face it Mercedes are also the quickest in high down force sectors as well. If Red Bull can't beat The Mercedes in Barca, then we can wheel the fat lady onto the stage.

TBH, i found the whole facade farcical. why then other renault teams (i.e CT and Lotus) are paying more than other 2 suppliers and getting less. renault engine management ant viry is in disarray i'd think with no real organisation as to what is customer right and what is works right.

TBH, i found the whole facade farcical. why then other renault teams (i.e CT and Lotus) are paying more than other 2 suppliers and getting less. renault engine management ant viry is in disarray i'd think with no real organisation as to what is customer right and what is works right.

How do you know that CT and Lotus are paying more than TR/RB?

RB have their Infiniti sponsorship in place so it makes sense they would pay less + they are the 'official works' team. TR on the other hand would probably be paying the same as CT/Lotus.

Red Bull have sent their own software team to help Renault resolve their issues with their PU which is predominately software related. So why would Red Bull want to share their own hard work, money and resources with their competitors? Why have CT and Lotus not done the same and if they've done the same, why not ask for equality then? I for one understand why Red Bull and TR get first dibs on the updates.

I think its foolish to think that CT and Lotus expect to get the latest PU when its their competitors resources that have been hard at work helping fixing the actual PU. It's like saying you've just spent $100k fixing a software bug/enhancement that your vendor had problems with and now you've help fixed it. Why would you want your competitors in the industry having it at the same time when you've just spent a $100k investment? What have your competitors done to deserve that?

It would not surprise me if there are different deals for all the engine manufacturers either. The same works for certain businesses in general, so I don't see why it couldn't be the same for engine supply that there are different deals.

Additionally, CT/Lotus and the rest of the Renault teams should re-negotiate a revised engine supply deal after the piss poor start Renault have had to the season as it has been detrimental for all the teams in terms of constructor points + prize money. For the most expensive PU out of the three manufacturers, they've received a lousy product.

As to whether I have proof that Renault are running separate works Customer deals the answer is no. But it's worth looking at available evidence. Red Bull Technologies embedded software analysts at Viry resulting in improved performance in Melbourne. Red Bull also prevented sharing of those updates with Lotus and Caterham. What I found most amusing was that Marko was quoted in AMUS that once Renault cut the power deficit to Mercedes to 40bhp they would be matching Mercedes AMG. Taffin's confirmed in Shanghai that their projected power deficit was now only 40bhp. It's interesting that for the past 3 seasons Red Bull have won the championship having a car with the lowest top speed of the leading runners. That approach might work if you can blow the diffusor, it does not look like it's going to work this year. Let's face it Mercedes are also the quickest in high down force sectors as well. If Red Bull can't beat The Mercedes in Barca, then we can wheel the fat lady onto the stage.

It's quite possible that the various teams are using different software but the hardware is still the same. In the age of the homologated engine they cannot supply different versions to their various customers.

Additionally, CT/Lotus and the rest of the Renault teams should re-negotiate a revised engine supply deal after the piss poor start Renault have had to the season as it has been detrimental for all the teams in terms of constructor points + prize money. For the most expensive PU out of the three manufacturers, they've received a lousy product.

actually your last paragraph sums up what i was trying to say. forget performance gains, lotus and CT needed new software mapping just to run the car uninterrupted. yes you can argue that RBR-STR programmers should be entitled to keep their fruits of labor for themselves, but at that point in time, it was more about getting other teams running.

regarding costs, i was alluding to what you wrote, off all the 3 manufacturers, renalut PU is the expensive one and most troublesome. they should seek compensation.

also interesting to note is that merc PU is supposed to be sacrificing around 15-20 HP because of the shorter exhaust manifold. (from the autosprint article posted above). also that merc compressor is larger. but due to bad google translation, i couldn't understand most of it, and weather it has any benefit. it says something about RPM and engine breaking and how merc MGU-H can bypass the battery and provide power directly to MGU-K and how the compressor bleed off can give more juice to MGU-K.

can anyone with italian knowledge please translate it better than google translate.

others who are more proficient in Italian will add to this, and perhaps point out a mistake or two, but here in bullet points, what I read from the linked article.

the article points out 4 main areas/benefits of the Mercedes PU

- the split turbo compressor/turbine are on opposite sides of the engine, which reduces/eleiminates the "heat flux" from the hot turbine side of the turbo, into the charge (compressed air) on the compressor side. This reduces the charge temperature for the same "work done" by the compressor (boost). Which in turn means, that you can reduce the inter cooling required to get the intake (into the engine) air temperature you want.

- unique intercooler solution, a additional benefit of the "split turbo" is, that the plumbing (pipe work) on the intake side is very short and compact, and that it allows the use of a new intercooler concept. The intercooler(s) appear to sit inside the chassis ( this part I don't fully understood, I think I know what they mean, but someone else with a better command on the Italian language may want to expand on this), and are "feed" by some duct work from the side pods. This solution, requires a rather unique "shape" of the chassis /tub, but has another benefit, as it doesn't obstruct the exit air flow from the main radiators (water coolers). Along the same lines, it is mentioned, that the main advantage from the "log style" exhaust comes from the compact packaging it allows. While they say/claim/estimate that this solution may "cost" between 15-20hp in outright engine performance, when seen from a "pure" engine point of view, the overall benefits outweigh the handicap the solutions bring. Again, the exhaust headers, are less obstructive to the airflow which comes from the main radiators on their way out of the cooling outlet towards the rear of the bodywork, and thereby allow for slimmer/narrower bodywork in this area, which benefits the aerodynamic of the car, both internal and external.

- they claim, that Mercedes is using a large® turbine then their opponents which let them extract more of the energy/power which is in the exhaust gas flow. The PU appears to be designed in a way, that it was the "plan" from the outset, to make this a integral part of the overall PU usage strategy. In the above posted energy flow schematic, you can see, that the energy flow from the MGU-H to the MGU-K is unrestricted by the rules. The only limitation is, that the total contribution of the MGU-K to the tractive/motive power (everything that propels the car forward) is capped at 120 kW. If the energy/power to the MGU-K comes out of the ES (battery) then there are additional limitations in place, as far as the energy flow is concerned.

This means, that you have a "upper limit" (time) of how long you can feed energy from the ES (battery) to the MGU-K.

But, as long as the energy comes directly out of the MGU-H and is feed directly into the MGU-K this limitation doesn't apply.

They estimate that Mercedes can augment their motive power for 50s per lap via the MGU-K, while the other teams (engine manufacturers) can do so, only for 36s.

One of the reasons is their larger turbine, which let them extract more energy from the exhaust gas flow, together with an "good" MGU-H and a refined control strategy to blend the MGU-K power with the ICE (engine) power.

- the last point is, a "clever" strategy to control the "waste gate" valve, and in general a quite elaborated and holistic control strategy which allows the power which is captured via the turbine/MGU-H to be blended via the MGU-K with the power which comes from the ICE (engine) part of the PU.

If they feed power directly from the MGU-H to the MGU-K any change in MGU-H rotational speed, will directly affect the overall power at the wheels (think traction).

In order to make this as smooth and predictable as possible, you need very good control over both parts of the PU.

You can think that the power (or torque if you prefer) at the input to the gearbox, and thereby at the wheels is the sum of the power from the engine (ICE) and MGU-K.

Total power = ICE+MGU-K

In order to be able to modulate this, and in order to give the driver good and predictable "feedback" to whatever he does with his throttle pedal, you need to have control over both the ICE and the MGU-K.

The power output of the engine, can be controlled via things like ignition timing &/or injection timing and amount of injected fuel.

The contribution of the MGU-K, you can control via the CE (Control Electronic), but this applies mainly if the energy comes out of the ES (battery) or, and this is where the waste gate control comes into the picture, you can control how fast the MGU-H spins, which in turn dictates how much power it will produce.

If you run the MGU-H (which works like a generator in this case) directly coupled to the MGU-K (which runs like a electric motor in this case) then, any change to the amount of power the generator produces, has a instant effect on how much power the motor delivers, and in turn how much power is available at the rear wheels.

And therein lies the "trick/secret" apparently. Mercedes is able to control the amount of power the MGU-H generates very precisely via a smart "waste gate" control strategy. This may also involves the actually waste gate as a hardware part, which could be different to waste gates used by the other manufacturers.

The other option, is to use the CE (control electronic) to "direct" the power from the MGU-H to the ES (battery) if it is not needed at the MGU-K, but this will be greatly affected by the "state of charge" of the ES. If the ES is "full" you can't dump any excessive power into the ES, and if you do, it will generate extra losses and heat (cooling requirements) in both the control electronic and the ES (battery) itself. So being able, to control the amount of energy the MGU-H produces and contributes to the overall "power budget" of the PU, via a clever waste gate operation, has it's merits, even if it just means, that "all what you do" is reducing the thermal stress on your control system , and produce less heat "under the skin" of your car.

The waste-gate will just dump the excessive exhaust gas, with all it's heat and energy out of the tail pipe - simple.

Any other strategy would first "extract" the energy (causing heat in the MGU-H) and then trying to "dump" it somewhere within the system, in this case trying to store it into the battery, which in turn means, that it creates additional loses, speak heat, in the control electronics, the cables and perhaps even the ES itself ( if this is the case or not, will depend on the type of ES used, capacitor vs. battery and the chemical process used in the battery). As an extreme example, Renault initially had planed to "dump" any excessive energy/power into a resistor, in case the ES couldn't take the energy at this moment. Now, dumping anywhere between 20-80 kW into a resistor (a element which turns electric energy into heat) produces a "hell of an toaster", and was one of the reasons, their customer teams suffered from massive overheating issues during the first test.

regarding the intercooler design, when one wants more cooling, one has to use large radiator that takes lot of space.also, large radiators create large back pressure. perhaps mercs were able to use shaped radiater that has even shallower angle than say RBR ones and the area behind the radiator is small compared to others which gives the radiator exhaust a smoother path to exit the car.

For anyone asking for Proof that Renault are offering separate works customer deals, may I point you to the front page article where Lopez gives an insight into their Renault customer supply. He CONFIRMS that Lotus only received the units Red Bull have been using since the start in China.
Ergo Red Bull have only been giving away 40bhp to Mercedes since the start of the season.
It's the software within the ECU ROM that is separating the Renault Power Units.

others who are more proficient in Italian will add to this, and perhaps point out a mistake or two, but here in bullet points, what I read from the linked article.

Awesome article, thanks!

IMO, I think it's more of the concept of how Mercedes envisioned their engine.... and their expertise. Thousands of units on the road provide you with invaluable experience on how to balance all the different components on these new PU.

For example, having a larger turbine certainly has its benefits, but they inherently have more mass and more rotational inertia. The turbine, compressor, exhaust, intake, MGUH and MGUK all have to be sized accordingly to gain any benefit from it.

The Mercedes PU of this year is a brilliant piece of machinery... and I'm a Ferrari fan.

For anyone asking for Proof that Renault are offering separate works customer deals, may I point you to the front page article where Lopez gives an insight into their Renault customer supply. He CONFIRMS that Lotus only received the units Red Bull have been using since the start in China. Ergo Red Bull have only been giving away 40bhp to Mercedes since the start of the season. It's the software within the ECU ROM that is separating the Renault Power Units.

Red Bull had the updated engines for Bahrain. Lotus and Caterham recieved them for China.

Anything Horner puts in the public domain needs very careful scrutiny. The implication is that the lack of straight line speed is purely down to a power deficit. Half the deficit is due to excessive drag of the Red Bull. It's Newey's emphasis on down force that is yet to pay off since the Mercedes cars are faster through the high down force sectors as well.

Anything Horner puts in the public domain needs very careful scrutiny. The implication is that the lack of straight line speed is purely down to a power deficit. Half the deficit is due to excessive drag of the Red Bull. It's Newey's emphasis on down force that is yet to pay off since the Mercedes cars are faster through the high down force sectors as well.

I'm also beginning to believe that it's not all down to Renault.

They may have to re-optimize their car around a lower L/D ratio for improved straight line speed and better fuel consumption.

Of course it's not all down to Renault, STR demonstrates that. You can have high top speeds with a Renault engine, you'll still be slow though. Just in a different way.

Doesn't mean the Renault isn't down on power. Straight line speed isn't the only way to judge power. What people don't realize when talking about that, is that you can have a higher drag setup but the higher power engine is still going to help power that through the straights, the same way it would on a car that has a low drag aero package. Mercedes could strap on their high downforce config, but they'd still have higher top speeds than they would with a Renault engine.

It used to be up in the air back in 2009 or 2010. I could understand the discussions about it. After this winter it became blatantly obvious, that the Renault is a liability.

Therefore Horner doesn't need to exaggerate anything, and I'm not even sure why I am typing this. It's sort of embarressing. It's been plainly obviously the beginning of the season, everyone in the paddock pretty much unanimously agrees and I wouldn't even see any point discussing it on here, because there's little room for grey area. The only grey area could be how much they are actually down, and that's hard to discuss because it changes every race weekend.. as Renault seem to improve more and more as time goes on. They are catching up, but still behind.

But yes.. Redbull's lack of top speed isn't ALL due to the engine, some weekends they have run a higher downforce higher drag aero setup.

edit - This post was a bit of an overreaction, not so much to any posts in this topic but the overall vibe that seems to pop up from time to time here. Of things that appear obvious, yet I come here and people need things spelled out for them. Things that leave little room for debate. It's annoying, but anyways..

Not trying to detract from the OP.. I found the OP's info very interesting.

Anything Horner puts in the public domain needs very careful scrutiny. The implication is that the lack of straight line speed is purely down to a power deficit. Half the deficit is due to excessive drag of the Red Bull. It's Newey's emphasis on down force that is yet to pay off since the Mercedes cars are faster through the high down force sectors as well.

It's a setup thing and a bad compromise from Red Bull. Merc isn't faster through the downforce sectors, RB are on their case. Watch China S2, no difference between them at all. But the overall balance is much better, Merc is pulling a massive gap in the speed traps. Truth is in a bit of both, RB probably lacks power but with such a downforce config it's just expected to see them fall back on the straights.

JetKing you have a valid point. Checking the sector times from quali 3, Riciardo gave up around 2 tenths to Hamilton in sector 2 and another half second in sector 3. I guess if Renault can cut the power deficit by another 20 bhp by Barcelona it could be game on as we can then see which design philosophy is superior between Red Bull and Mercedes.
As an aside, on the topic of power units, I can see a flaw in the Auto sprint article. Bear with me as my science back ground is not mech engineering. The 36 second figure seems to be an Extrapolation of the ERS to a KERS system. 4Mega joules will only give a 33 second output from a 120KW motor.
If you read the Cosworth study from their V6 engine, a greater proportion of the energy available for storage is used in the MGU-KINETIC and MGU-HEAT, with only 45kW stored by the ES. As I understand it the ES is then only used as a top up when the car is no longer traction limited.

In summary the Mercedes powerunits split turbo arrangement is a performance differentiator but it's decisions that the team have made in the rest of the installation that sets them apart from even those teams that also run the Mercedes HPP unit giving them not only a power advantage but creating a more internally aerodynamic efficient car. ....

with the Renault and Ferrari powered teams struggling generally with the transition of energy under acceleration and braking. This affects the brake-by-wire system, as holes in the provision of energy or during harvesting will lead to communication issues between the MGU-H, MGU-K, ES, controller and braking system ...

With the Renault and Ferrari powered teams having issues that really revolve around larger packaging and problems with the ERS, fixing either of these issues during the 2014 season will not only be vast and expensive but come with their own compromises.

It's a setup thing and a bad compromise from Red Bull. Merc isn't faster through the downforce sectors, RB are on their case. Watch China S2, no difference between them at all. But the overall balance is much better, Merc is pulling a massive gap in the speed traps. Truth is in a bit of both, RB probably lacks power but with such a downforce config it's just expected to see them fall back on the straights.

If Red Bull's RB10 is running more down force, yet still losing out slightly in the down force dependent S2 sector, that implies that the Mercedes W05 is aerodynamically the better package, as they are faster/similar in the same sector while running less wing.

If Red Bull's RB10 is running more down force, yet still losing out slightly in the down force dependent S2 sector, that implies that the Mercedes W05 is aerodynamically the better package, as they are faster/similar in the same sector while running less wing.